Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
  • C23C14/08—Oxides
  • C23C14/083—Oxides of refractory metals or yttrium
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
  • C23C14/08—Oxides
  • C23C14/087—Oxides of copper or solid solutions thereof
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
  • C23C14/34—Sputtering
  • C23C14/46—Sputtering by ion beam produced by an external ion source
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N60/00—Superconducting devices
  • H10N60/01—Manufacture or treatment
  • H10N60/0268—Manufacture or treatment of devices comprising copper oxide
  • H10N60/0296—Processes for depositing or forming copper oxide superconductor layers
  • H10N60/0408—Processes for depositing or forming copper oxide superconductor layers by sputtering
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N60/00—Superconducting devices
  • H10N60/01—Manufacture or treatment
  • H10N60/0268—Manufacture or treatment of devices comprising copper oxide
  • H10N60/0296—Processes for depositing or forming copper oxide superconductor layers
  • H10N60/0576—Processes for depositing or forming copper oxide superconductor layers characterised by the substrate
  • H10N60/0632—Intermediate layers, e.g. for growth control
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T50/00—Aeronautics or air transport
  • Y02T50/60—Efficient propulsion technologies, e.g. for aircraft
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S505/00—Superconductor technology: apparatus, material, process
  • Y10S505/725—Process of making or treating high tc, above 30 k, superconducting shaped material, article, or device
  • Y10S505/73—Vacuum treating or coating
  • Y10S505/731—Sputter coating

Definitions

• the present invention relates to a method for producing a polycrystalline thin film having a uniform crystal orientation and a method for producing an oxide superconducting conductor.
• This application is based on a patent application to Japan (Japanese Patent Application No. 8-281801), the contents of which are incorporated herein by reference. I do. Background art
• Oxide superconductors discovered in recent years are excellent superconductors that exhibit a critical temperature exceeding the temperature of liquid nitrogen, but at present, this type of oxide superconductor is being used as a practical superconductor. There are various problems to be solved. One of the problems is that the critical current density of oxide superconductors is low.
• an oxide superconducting layer having a favorable crystal orientation is formed on the substrate, and It is necessary to orient the a-axis or b-axis of the crystal of the oxide superconducting layer in the direction in which electricity is to flow, and orient the c-axis of the oxide superconductor in the other direction.
• various means have been attempted to form an oxide superconducting layer having good crystal orientation on a substrate such as a substrate or a metal tape.
• One method similar M g O or S r T i 0 using a single crystal substrate such as 3, film formation method such as sputtering on these single crystal substrate of oxide than conductors and crystal structure To form oxide superconducting layer Has been implemented.
• an oxide superconducting layer is formed directly on a base material such as a metal tape, the metal tape itself is polycrystalline and its crystal structure is significantly different from that of the oxide superconductor.
• the oxide superconducting layer cannot be formed at all.
• the heat treatment performed during the formation of the oxide superconducting layer causes a diffusion reaction between the metal tape and the oxide superconducting layer, thereby breaking the crystal structure of the oxide superconducting layer and deteriorating the superconducting characteristics. .
• the oxide superconducting layer formed on this type of intermediate layer by a sputtering apparatus has a much lower critical current density than the oxide superconducting layer formed on a single crystal substrate (for example, several hundred to (Approximately 0 0 0 O AZ cm 2 ). This is considered to be due to the following reasons. Fig.
• FIG. 14 shows an oxide superconducting conductor in which an intermediate layer 2 is formed on a base material 1 such as a metal tape by a sputtering device, and an oxide superconducting layer 3 is formed on the intermediate layer 2 by a sputtering device. It shows a cross-sectional structure.
• the oxide superconducting layer 3 is in a polycrystalline state, and many crystal grains 4 are in a state of being randomly combined. Looking at each of these crystal grains 4 individually, the c-axis of the crystal of each crystal grain 4 is oriented perpendicular to the substrate surface, but the a-axis and b-axis are oriented in random directions. And It is considered to be.
• the reason why the oxide superconductor is in a polycrystalline state in which the a-axis and b-axis are not oriented is because the intermediate layer 2 formed thereunder is in a polycrystalline state in which the a-axis and the b-axis are not oriented. This is probably because when the oxide superconducting layer 3 is formed, the oxide superconducting layer 3 grows to match the crystal of the intermediate layer 2.
• techniques for forming various alignment films on a polycrystalline base material are used. For example, in the fields of optical thin films, magneto-optical disks, wiring boards, high-frequency waveguides, high-frequency filters, and cavity resonators.
• the challenge is to form a good polycrystalline thin film. That is, if the crystal orientation of the polycrystalline thin film is good, the quality of the optical thin film, the magnetic thin film, the wiring thin film, etc. formed thereon is improved, and the crystal orientation is further improved on the base material. It is more preferable that an optical thin film, a magnetic thin film, a thin film for wiring, and the like can be directly formed. Therefore, the present inventors formed a polycrystalline thin film of yttria-stabilized zirconia (hereinafter abbreviated as YSZ) on a base material of a metal tape, and formed an oxide superconducting layer on the polycrystalline thin film. Various attempts have been made to produce oxide superconducting conductors with excellent superconducting properties.
• YSZ yttria-stabilized zirconia
• Japanese Patent Application Laid-Open Nos. HEI 4-299865 Japanese Patent Application No. 3-128686
• No. 795 Japanese Patent Application No. 3-126673
• Japanese Patent Application Laid-Open No. 4-9005 Japanese Patent Application No. 2-2055551
• Japanese Patent Application No. 6-39 In Japanese Patent Application No. 368
• Japanese Patent Application No. 4 _ 1 3 4 4 3 Japanese Patent Application Laid-Open No. 6-145 797
• particles of YSZ are deposited on a substrate.
• a polycrystalline thin film having excellent crystal orientation can be formed.
• the present inventors have been conducting research for producing a long or large-area polycrystalline thin film and an oxide superconducting conductor.
• the present inventors have achieved the present invention as a result of conducting research on a method of manufacturing a polycrystalline thin film and obtaining a superconducting layer having a superconducting property that is superior to that of a conventional method when a superconducting layer is formed on the polycrystalline thin film.
• the present invention has been made to develop the technology of the patent application and to effectively solve the above-mentioned problems, and has a crystal axis C perpendicular to the film-forming surface of the substrate.
• a polycrystalline thin film with excellent crystal orientation can be provided because the axes can be oriented and the a-axis and b-axis of the crystal grains can be aligned along a plane parallel to the film-forming surface.
• Another object of the present invention is to provide an apparatus for producing a polycrystalline thin film having excellent crystal orientation. Disclosure of the invention
• the present invention provides a method for depositing particles generated from a sunset on a base material and forming a polycrystalline thin film comprising the constituent elements of the sunset on the base material.
• the ion beam generated by the ion source is irradiated obliquely at an incident angle in the range of 50 to 60 degrees with respect to the normal to the film deposition surface of the substrate.
• the temperature at the time of film formation is set at 300 ° C. or less.
• a target of yttrium-stabilized zirconium can be used.
• the method for producing an oxide superconducting conductor of the present invention deposits particles generated from a gate on a substrate, and forms on the substrate a material comprising the constituent elements of the gate.
• an ion source is generated when particles of one-gate are deposited on a substrate.
• the particles are deposited while irradiating the formed ion beam from an oblique direction at an incident angle in the range of 50 to 60 degrees with respect to the normal to the film forming surface of the base material to form a polycrystalline thin film.
• the temperature at the time of film formation is set at 300 ° C. or lower, and after forming a polycrystalline thin film, an oxide superconducting layer is formed thereon.
• a target of yttrium-stabilized zirconia can be used.
• the thickness of the polycrystalline thin film formed on the substrate is set to 200 nm or more.
• an ion beam is irradiated at an incident angle of 50 to 60 degrees with respect to the normal to the film formation surface of the substrate when depositing the particles generated from the evening gate on the substrate. Since the film formation temperature is set to 30 or less, the grain boundary inclination angle of 35 degrees or less that improves not only the c-axis orientation but also the a-axis orientation and the b-axis orientation with respect to the deposition surface of the substrate A YSZ polycrystalline thin film can be reliably obtained.
• a film having a good film quality can be obtained. That is, If the film is a magnetic film, a magnetic film having good magnetic characteristics can be obtained. If the film is an optical thin film, an optical thin film having excellent optical characteristics can be obtained.
• yttrium-stabilized zirconia can be specifically used as a material generated from the gate and deposited on the substrate, and a polycrystalline thin film of yttrium-stabilized zirconia having excellent crystal orientation can be used. Obtainable.
• the thickness of the obtained polycrystalline thin film is 200 nm or more, a polycrystalline thin film having sufficiently excellent crystal orientation can be reliably obtained.
• an oxide superconducting layer with good orientation formed at the above-described temperature an oxide superconducting layer with good crystal orientation can be generated, and the critical current An oxide superconductor having a high density and good superconducting properties can be obtained.
• the polycrystalline thin film As a specific example of the polycrystalline thin film, yttrium-stabilized zirconium can be used. If the thickness of the obtained polycrystalline thin film is 200 nm or more, an oxide superconducting conductor having a high critical current density and a polycrystalline thin film having sufficiently excellent crystal orientation can be obtained. .
• An apparatus includes: a film forming processing container; a sending device provided in the film forming processing container to feed a tape-shaped long base material into the inside of the film forming processing container; A winding device for winding the base material, a base material holder provided between the sending device and the winding device, the base material holder being in contact with the back surface side of the base material discharged from the sending device and guiding the base material; A target for disposing particles on the surface of the substrate, which is disposed opposite to the surface side of the substrate guided by the material holder; An ion source for irradiating an ion beam within a predetermined angle range from a direction, and a cooling device for cooling the substrate by cooling the substrate holder.
• the cooling device is connected to the hollow base for mounting the base material holder, and is drawn out to the outside through the outer wall of the film formation processing container. And a refrigerant introduction pipe communicating with the internal space of the base and the external space of the film formation processing container.
• a coolant can be supplied to the base from the outside of the film formation processing container by a refrigerant supply pipe separately from the depressurized state inside the film formation processing container.
• a refrigerant supply pipe separately from the depressurized state inside the film formation processing container.
• the refrigerant introduction pipe may communicate with the internal space of the base to introduce a refrigerant
• the refrigerant introduction pipe may communicate with the internal space of the base and surround the outward pipe to form a film forming chamber. It has a double structure consisting of a return pipe communicating with the external space of the vessel. By having a double structure that covers the outgoing pipe with the return pipe, the outgoing pipe can be cooled by the refrigerant passing through the return pipe and the vaporized gas. Temperature rise can be prevented.
• FIG. 1 is a cross-sectional view showing a polycrystalline thin film of YSZ formed by the method of the present invention.
• FIG. 2 is an enlarged plan view showing crystal grains of the YSZ polycrystalline thin film shown in FIG. 1, their crystal axis directions and grain boundary tilt angles.
• FIG. 3 is a configuration diagram showing an example of an apparatus for producing a polycrystalline thin film on a substrate by performing the method of the present invention.
• FIG. 4 is a sectional view showing an example of an ion gun provided in the apparatus shown in FIG.
• FIG. 5 is a cross-sectional view showing an example of a cooling device provided in the device shown in FIG.
• FIG. 6 is a cross-sectional view showing the oxide superconducting layer formed on the YSZ polycrystalline thin film shown in FIG.
• FIG. 7 is an arrangement diagram of an X-ray apparatus for measuring the crystal orientation of a polycrystalline thin film.
• FIG. 8 is a pole figure of a polycrystalline thin film formed at 100 ° C. with an ion beam incident angle of 55 ° and an ion beam energy of 300 eV.
• FIG. 9 is a pole figure of a polycrystalline thin film formed at 200 ° C. with an ion beam incident angle of 55 ° and an ion beam energy of 300 eV.
• FIG. 10 is a pole figure of a polycrystalline thin film formed at 300 ° C. with an ion beam incident angle of 55 ° and an ion beam energy of 300 eV.
• FIG. 11 is a pole figure of a polycrystalline thin film formed at 400 ° C. with an ion beam incident angle of 55 ° and an ion beam energy of 300 eV.
• FIG. 12 is a pole figure of a polycrystalline thin film formed at 500 ° C. with an ion beam incident angle of 55 ° and an ion beam energy of 300 eV.
• FIG. 13 is a diagram showing the relationship between the thickness of the polycrystalline thin film formed on the substrate and the full width at half maximum.
• FIG. 14 is a graph showing the relationship between the incident angle of the ion beam and the full width at half maximum of the obtained polycrystalline thin film.
• FIG. 15 is a configuration diagram showing a polycrystalline thin film and an oxide superconducting layer formed on a substrate by a conventional method.
• FIG. 17 is a diagram showing the relationship between the full width at half maximum and the film thickness of the polycrystalline thin film obtained by the method of the present invention.
• FIG. 18 is a pole figure of a polycrystalline thin film formed at an ion beam incident angle of 55 degrees and an ion beam energy of 300 eV at o.
• FIG. 1 shows an example of a structure in which a polycrystalline thin film of YSZ (yttrium-stabilized zirconia) is formed on a substrate by performing the method of the present invention.
• A is a tape-shaped substrate.
• B shows a polycrystalline thin film formed on the upper surface of the substrate A.
• the base material A is a tape-shaped material, but, for example, various shapes such as a plate material, a wire material, a strip can be used, and the base material A is silver, platinum, It is made of various metal materials such as stainless steel, copper, nickel alloys such as Hastelloy, etc., or various glasses or various ceramics.
• a large number of fine crystal grains 20 such as YSZ having a cubic crystal structure or CeO 2 are joined and integrated with each other via crystal grain boundaries.
• the c axis of the crystal axis of each crystal grain 20 is oriented at right angles to the upper surface (deposition surface) of substrate A, and the a axis and b axis of the crystal axis of each crystal grain 20 are mutually They are oriented in the same direction and in-plane.
• the a-axis (or b-axis) of each crystal grain 20 is joined and integrated at an angle (grain boundary tilt angle K shown in Fig. 2) of 35 degrees or less.
• FIG. 3 is a diagram showing an example of a polycrystalline thin film manufacturing apparatus suitably used for carrying out the polycrystalline thin film manufacturing method of the present invention.
• the apparatus for producing a polycrystalline thin film in this example includes a block-shaped substrate holder 23 that supports the tape-shaped substrate A and can be heated or cooled to a desired temperature, and a tape on the substrate holder 23.
• the base material holder 23 is provided with a built-in heater 23 a made of a metal wire or the like that generates resistance heat when energized, and requires a tape-shaped base material A sent out onto the base material holder 23. It can be heated to a desired temperature accordingly.
• Such a base material holder 23 is disposed in an optimum irradiation area of the ion beam irradiated from the ion source 39 in the film formation processing container 40.
• the base material holder 23 is mounted on a triangular base 60, and the base 60 is provided with a coolant introduced through the outer wall 40a of the film forming vessel 40.
• a cooling device R is supported by the tube 61 at the center of the film-forming processing container 40, and includes the base 60 and the refrigerant introduction tube 61 as main components.
• the base 60 of this embodiment is made of a hollow metal block having a triangular cross section as shown in FIG. 5, and its upper surface 60a has an incident angle of 50 to 60 degrees with respect to a base material of an ion beam described later.
• a refrigerant introduction pipe 61 is connected to the rear surface 60 b of the base 60, and the refrigerant introduction pipe 61 is a double pipe composed of an internal outgoing pipe 62 and a return pipe 63 covering the outside thereof.
• the outgoing pipe 62 and the return pipe 63 are both connected to the internal space of the base 60 inside the chamber, and both of them extend almost horizontally to form a film.
• the outer pipe 40 a is penetrated to the outside through the outer wall 40 a of the processing vessel 40, and both pipes are curved upward at the outside, and the tip of the forward pipe 62 is slightly higher than the tip of the return pipe 63.
• An injection portion 64 is formed so as to protrude, and a funnel-shaped injection member 65 is further attached to the injection portion 64.
• Both the tip of the outgoing pipe 62 on the base 60 side and the tip of the return pipe 63 on the base 60 side are air-tightly joined to the connection holes on the back 60 b of the base 60. Therefore, even when the inside of the film formation processing container 40 is depressurized, the inside of the base 60 can be brought into the atmospheric pressure state outside the film formation processing container, and the liquid inside the injection member 65 described above can be maintained. Liquid cooling such as nitrogen A medium or a gaseous refrigerant such as cooling air is sent in so that the inside of the base 60 can be filled with the refrigerant.
• the outgoing pipe 62 and the return pipe 63 are provided because when the refrigerant introducing pipe 61 is composed of only the outgoing pipe 62, liquid nitrogen is injected into the injection member 65, and the base is moved from the outgoing pipe 62 to the base. Even if liquid nitrogen is to be supplied to 60, the liquid nitrogen or vaporized nitrogen gas that has been supplied earlier will stay inside base 60, and it will not be possible to supply new liquid nitrogen to base 60. This is to prevent that. If a return pipe 63 is provided at this point, it is easy to discharge the old liquid nitrogen or vaporized nitrogen gas remaining in the base 60 to the atmosphere via the return pipe 63. Therefore, fresh liquid nitrogen can be constantly supplied to the base 60 to sufficiently cool the base 60, and the cooling capacity can be increased.
• a temperature measuring device 67 for measuring the temperature of the base 60 is mounted on the flange plate 66 so as to be adjacent to the refrigerant supply pipe 61, and the temperature connected to the temperature measuring device 67
• the sensor 68 is configured to measure the temperature of the substrate holder 23. That is, when the substrate holder 23 is set on the upper surface 60a of the base 60 as shown by a two-dot chain line in FIG. 5, the temperature sensor 68 can be brought into contact with the substrate holder 23. It is configured so that the temperature of the substrate holder 23 can be measured.
• a cooling device using a fluorine-based gas such as chlorofluorocarbon or ammonia used in a normal cooling device such as a cooler is used. Needless to say, a device capable of cooling to about ° C may be provided.
• the substrate is heated spontaneously due to high-temperature particles coming from the evening getter. For example, if the film is formed at room temperature and the substrate holder is not heated or cooled at all, Will be heated to about 100 ° C. In the case where the film is formed while cooling with liquid nitrogen, the ability to cool the substrate A from the substrate 60 can be adjusted by adjusting the material and thickness of the substrate holder 23 that supplies the substrate.
• the heat generated during film formation can be reduced by one hundred fifty-five. It can be easily cooled to about ° C.
• the cooling capacity from the base 60 can be suppressed low. Even if a liquid nitrogen refrigerant is used, the temperature of the substrate A can be easily adjusted to about -150 to 150 Ot.
• the tape-shaped substrate ⁇ ⁇ is continuously fed from the substrate delivery bobbin 24 onto the substrate holder 23 and passed through the optimal irradiation area.
• the polycrystalline thin film B can be continuously formed on the base material A.
• the evening get 36 is for forming a target polycrystalline thin film, and may have the same composition or an approximate composition as the target polycrystalline thin film. Specifically targeting 3 6, M G_ ⁇ or Upsilon 2 0 3 with stabilized Jirukonia (YSZ), C E_ ⁇ 2, M G_ ⁇ , S r T I_ ⁇ 3 used such as, but limited shall thereto Instead, use a target appropriate for the polycrystalline thin film to be formed. 1 is fine.
• Such a target 36 is rotatably attached to a target support 36 a by a pin or the like, so that the tilt angle can be adjusted.
• the sputter beam irradiator (sputtering means) 38 is provided with a grid for accommodating an evaporation source inside the container and applying a drawing voltage near the evaporation source.
• the target 36 can be irradiated with an ion beam to strike out constituent particles of the target 36 toward the base material A.
• the ion source 39 has substantially the same configuration as the sputter beam irradiation device 38, and includes a grid for storing an evaporation source inside the container and applying a drawing voltage near the evaporation source. It is configured.
• the apparatus that ionizes a part of atoms or molecules generated from the evaporation source, controls the ionized particles by an electric field generated by a grid, and irradiates them as an ion beam.
• ionizing particles such as a DC discharge method, a high-frequency excitation method, a filament method, and a class ion beam method.
• the filament type is a method in which a tungsten filament is energized and heated to generate thermoelectrons, which collide with evaporated particles in a high vacuum to ionize.
• a class of aggregated molecules coming out of a nozzle provided in the opening of a crucible containing raw materials is bombarded with thermoelectrons and emitted as ions. .
• an ion source 39 having the internal structure shown in FIG. 4 is used.
• the ion source 39 includes a tubular lid 46, a filament 46, and an introduction pipe 48 for Ar gas or the like inside a cylindrical ion chamber 45, and a beam port at the tip of the ion chamber 45. From 49, ions can be emitted in a beam shape almost in parallel.
• the installation position of the ion source 39 can be changed, and the diameter d of the beam port 49 can also be changed.
• the ion source 39 has its center axis S formed at an incident angle 0 (perpendicular (normal) H of the base A and the center line S) with respect to the film-forming surface of the base A. At an angle).
• This incident angle 0 is preferably in the range of 50 to 60 degrees. But more preferably in the range of 55-60 degrees, most preferably 55 degrees. Therefore, the ion source 39 is arranged so as to be able to irradiate the ion beam at a certain incident angle 0 with respect to the normal H of the film forming surface of the substrate A.
• the ion source 39 has a divergence angle of an ion beam to be emitted from the ion source 39, which is represented by the following formula (I).
• ⁇ 0 is the spread angle of the ion beam
• d is the beam diameter (cm) of the ion source 39
• L is the ion beam transport distance, which is the distance between the beam port 49 of the ion source 39 and the substrate A. (Cm).
• the transport distance L and beam diameter d of the ion beam are set according to the desired crystal orientation of the polycrystalline thin film.
• the ion beam irradiated onto the base material A by the ion source 39 is a rare gas ion beam such as He +, Ne +, Ar +, Xe + , Kr + or the like when the intermediate layer of YSZ is formed, or good in a mixed ion beam thereof and oxygen ions, but especially in the case of forming the intermediate layer C E_ ⁇ 2, Kr + ion beam, or using a K r + and Xe + mixed ion beam.
• the film forming process container 40 includes a single pump 51 and a cryopump 52 for bringing the inside of the film forming process container 40 into a low pressure state such as a vacuum, and an atmosphere gas supply source such as a gas cylinder.
• the inside of the film formation processing container 40 can be kept in a low pressure state such as a vacuum and an argon gas or other inert gas atmosphere or an inert gas atmosphere containing oxygen.
• a current density measuring device 54 for measuring a current density of an ion beam in the film forming processing container 40 and a pressure in the container 40 are provided in the film forming processing container 40.
• a pressure gauge for measurement 55 is installed.
• an angle adjusting mechanism is attached to a support portion of the ion source 39 to adjust the inclination angle of the ion source 39 and adjust the incident angle of the ion beam.
• the angle adjusting mechanism may have various configurations.
• the transport distance L of the ion beam can be changed.However, the length of the support 23a of the base holder 23 can be adjusted. The transport distance L of the ion beam may be changed.
• the internal YSZ or C e 0 such becomes evening with one target 3 6 2, deposited accommodates a base material A processing vessel 4 0 Is evacuated to a reduced-pressure atmosphere, the base material A is sent out from the base material delivery bobbin 24 to the base material holder 23 at a predetermined speed, and the ion source 39 and the sputtering beam irradiating device 38 are further set up. Activate. Further, the temperature of the substrate A in contact with the substrate holder 23 is adjusted to the following desired temperature at 300 by operating a heating heater or a cooling device attached to the substrate holder 23.
• the set temperature of substrate A should be set as low as possible even within the range of 300 ° C or less. preferable.
• the film formation temperature is set at 300 ° C. or less, a temperature range of 100 ° C. or less, which indicates the substrate temperature when the substrate A is not particularly heated by the substrate holder 23 at room temperature, is preferable. It can be easily cooled by liquid nitrogen which can be used inexpensively as a refrigerant—a temperature range of 150 ° C. or more is a more preferable set temperature.
• the heated state by the deposited particles or the film forming processing container 40 using liquid nitrogen by heat radiation from other devices Even if a substrate holder that is as thin as possible is used, the temperature of the substrate A can only be cooled to about 150, so if cooling to a lower temperature, use another refrigerant such as liquid helium. Will be.
• the ion beam is irradiated from the sputter beam irradiation device 38 to the evening target 36, the constituent particles of the target 36 are beaten out and fly onto the substrate A.
• the constituent particles struck out of the target 36 are deposited on the base material A sent out onto the base material holder 23, and simultaneously, for example, mixing of Ar + ions and oxygen ions from the ion source 39.
• the polycrystalline thin film B having a desired thickness is formed by irradiating an ion beam, and the tape-shaped substrate A after film formation is wound around the substrate winding pobin 25.
• the incident angle 0 when irradiating the beam is preferably in the range of 50 to 60 degrees, more preferably in the range of 55 to 60 degrees, and most preferably 55 degrees. Assuming that 0 is 90 degrees, the c-axis of the polycrystalline thin film is oriented perpendicular to the deposition surface on substrate A, but the (1 1 1) Is not preferred.
• the polycrystalline thin film does not even have c-axis orientation.
• the ion beam is irradiated at the incident angle in the preferable range as described above, the (100) plane of the crystal of the polycrystalline thin film stands.
• the a-axis and the b-axis of the crystal axes of the YSZ polycrystalline thin film formed on the substrate A are directed in the same direction.
• the substrate A is oriented in-plane along a plane parallel to the upper surface (deposition surface) of the substrate A.
• the constituent particles of the target 36 provided in the film-formation processing container 40 capable of being evacuated are beaten out by sputtering, and the substrate A
• the ion beam generated from the ion source 39 is deposited while irradiating the ion beam at an incident angle of 50 to 60 degrees with respect to the normal H of the film forming surface of the substrate A.
• the method of forming a polycrystalline thin film on A by controlling the temperature of the substrate A to a desired temperature, a material having better crystal orientation can be obtained.
• the angle of incidence of the ion beam is adjusted by adjusting the inclination angle of the upper surface 60a of the base 60.
• a substrate temperature to 300 ° C
• a polycrystalline thin film of YSZ having a grain boundary inclination angle of 35 ° can be obtained.
• a YSZ polycrystalline thin film with a grain boundary inclination angle of 25 degrees can be obtained.
• a YSZ polycrystalline thin film with a grain boundary inclination angle of 18 degrees can be obtained.
• the temperature By setting the temperature to 0 ° C, it is possible to obtain a polycrystalline thin film of YSZ with a grain boundary inclination of 13 degrees, and by setting the temperature to 100 ° C, it is possible to obtain a polycrystalline thin film of YSZ with a grain boundary inclination of 10 degrees.
• a thin film can be obtained, and by setting the value to 150, a polycrystalline thin film of YSZ having a grain boundary inclination angle of 8 degrees can be obtained.
• the oxide superconducting layer 22 having the structure shown in FIG. 5 is obtained by laminating the oxide superconducting layer C on the polycrystalline thin film formed as described above by a film forming method such as sputtering / laser vapor deposition. Can be.
• the oxide superconducting layer C is coated on the upper surface of the polycrystalline thin film B, and the c-axis of the crystal grain 23 is oriented at right angles to the upper surface of the polycrystalline thin film B.
• the a-axis and the b-axis are oriented in-plane along the plane parallel to the upper surface of the base material as in the case of the polycrystalline thin film B described above, and the grain boundary tilt angle formed by the crystal grains 23 is formed to a small value.
• the oxide superconducting layer C formed on the polycrystalline thin film B has almost no disorder in the crystal orientation, and each of the crystal grains constituting the oxide superconducting layer C has a base material.
• the c-axis which is hard to conduct electricity, is oriented in the thickness direction of A, and the a-axis or b-axis is oriented in the length direction of the base material A.
• the obtained oxide superconducting layer C has excellent quantum coupling properties at the crystal grain boundaries and hardly deteriorates the superconducting properties at the crystal grain boundaries, so that it becomes easier to conduct electricity in the length direction of the base material A, A critical current density as high as that of an oxide superconducting layer formed on a single crystal substrate of MgO or SrTO : ⁇ can be obtained.
• a critical current density of the oxide superconducting layer of 800,000 AZcm 2 was obtained.
• a critical current density of the oxide superconducting layer of 250,000 A / cm 2 can be obtained.
• the YSZ polycrystalline thin film B has excellent crystal orientation and excellent critical current characteristics. Oxide superconducting conductor 22 can be obtained.
• the oxide superconductor obtained in this example has a long length with excellent flexibility. It can be easily formed into a loop shape and can be expected to be applied to windings of superconducting magnets.
• the present inventors assume the following as factors for adjusting the crystal orientation of the polycrystalline thin film B described above.
• the unit cell of the crystal of the polycrystalline thin film B of YSZ is cubic, and in this crystal lattice, the normal direction of the substrate is the ⁇ 100> axis, and the other is the ⁇ 110> axis. 0 0 1> axis is in the other direction.
• the diagonal direction of the unit cell with respect to the origin of the unit cell that is, along the ⁇ 111> axis
• the incident angle with respect to the substrate normal is 54.7 degrees.
• the full width at half maximum indicating the crystal orientation of the polycrystalline thin film of YSZ obtained according to the incident angle of the ion beam is obtained.
• the value shows a minimum value when the ion beam incident angle is in the range of 55 to 60 degrees.
• exhibiting good crystal orientation in the range of the incident angle of 50 to 60 degrees means that the ion beam incident angle coincides with or is about 54.7 degrees.
• the ion channeling occurs most effectively, and in the crystals deposited on the substrate A, only the atoms having the arrangement relationship corresponding to the above angle on the upper surface of the substrate A are likely to remain selectively. However, it is estimated that only those crystals with well-aligned atoms are selectively deposited and deposited as a result of the spattering effect of the ion beam to remove other disordered atomic arrangements. are doing.
• the irradiation effect of the ion beam on the YSZ has two effects, that is, the effect of erecting the (100) plane of the YSZ perpendicular to the base material and the effect of adjusting the in-plane orientation. It is presumed that the main effect is to precisely (100) plane perpendicular to the substrate. This is because if the effect of erecting (100) YSZ perpendicular to the substrate is insufficient, the in-plane orientation is inevitably disturbed.
• the value of the grain boundary inclination angle K of the polycrystalline thin film B becomes The inventor of the present application presumes the reason for the goodness, in other words, the reason for the good crystalline orientation of the polycrystalline thin film B as follows.
• the film forming atmosphere is set to a low temperature, for example, a temperature of about 400 to 600 ° C. or higher. It is common knowledge to form a film while heating the film. The fact that a film having high crystallinity is generally obtained by forming a film while heating to such a high temperature means that there is a close relationship between the film formation temperature and crystallization, It is understood that in the field of thin film production, when the film formation temperature is low, a film having a high degree of amorphousness is easily formed.
• the film forming temperature is preferably as low as possible because the effect of adjusting the crystal by the ion beam is extremely large. This is because, at lower temperatures, the movement and vibration of the atoms that make up the crystal are reduced, and the effect of aligning the crystal due to ion beam irradiation is more effectively exhibited. It is presumed that the crystalline thin film B is likely to be generated. That is, according to the technology of the present invention, it is possible to obtain a polycrystalline thin film in which the [100] axis is more stable as the temperature becomes lower, and accordingly, the angle of the [111] axis is uniquely determined.
• the polycrystalline thin film B having a higher crystal orientation can be obtained as the film formation temperature becomes lower, and the polycrystalline thin film B having a more excellent crystal orientation can be obtained when the polycrystalline thin film B is formed at a temperature of 100 or less.
• the fact that a thin film B can be obtained is inconsistent with the knowledge that it is difficult to obtain a film with high crystallinity without forming a film while heating it to a high temperature in general film forming technology.
• FIG. 3 Using an apparatus with the configuration shown in Figs. 3 to 5, sputtering with ion beam irradiation was performed to deposit a polycrystalline thin film of YSZ on a metal tape.
• Hastelloy C 276 tape with a mirror-finished surface of 10 mm in width, 0.5 mm in thickness, and several meters in length was used. Evening one target is YS Z (Y 2 ⁇ 3: 8 mol%) was used made of things, as well as sputtering evening by irradiating A r + ions from the ion gun to evening one rodents Bok, the incident angle of the ion beam from the ion gun set to the incident angle 55 degrees with respect to the normal of the deposition surface of the substrate tape on the substrate holder, K r + + 0 300 energy 2 ion beam e V, the ion current density 100 AZcm 2
• the laser beam is deposited on the substrate simultaneously with the ion beam irradiation, and the substrate tape is moved at a constant speed along the substrate holder to form a 1100 nm thick YSZ layer on the substrate tape.
• the heater of the substrate holder was operated to control the temperature of the substrate and the polycrystalline thin film at the time of film formation to 500, 400 ° C., 300 T, and 200 T, respectively.
• the temperature of the substrate and the polycrystalline thin film was maintained at 100 due to the ion beam irradiation effect and the heat generated from other parts inside the apparatus.
• the temperature of the substrate and the polycrystalline thin film was reduced to 0 ° C by cooling with liquid nitrogen using the cooling device shown in Fig. 5 and changing the thickness of the substrate holder used.
• a polycrystalline thin film was formed on a tape-shaped substrate by controlling the temperature to 100 and 150 ° C, respectively.
• X-rays are irradiated to the YSZ polycrystalline thin film formed on the substrate A at an angle of 0, and the X-rays are incident on a vertical plane including the incident X-rays.
• An X-ray counter-58 is set at an angle of 20 (58.7 degrees) to the incident X-ray, and the value of the horizontal angle ⁇ with respect to the vertical plane including the incident X-ray is appropriately changed, that is, In FIG. 7, the orientation between the a-axis and the b-axis of the polycrystalline thin film B was measured by measuring the diffraction intensity obtained by rotating by a rotation angle ⁇ as indicated by an arrow in FIG.
• the crystal orientation of each crystal grain of the obtained polycrystalline thin film of YSZ was examined.
• the diffraction peak was measured when the angle of ⁇ was set to a value of ⁇ 20 degrees to 20 degrees in increments of 1 degree.
• the in-plane orientation was determined based on whether or not the peak value appeared in a range of soil times and disappeared in a range of times.
• an oxide superconducting layer was formed on these polycrystalline thin films using an ion beam sputtering apparatus.
• Y as a target. 7 B a L 7 CU 3 ..
• the resulting oxide superconducting tape conductor has a width of 10.0 mm, length lm.
• This oxide superconducting tape conductor was cooled with liquid nitrogen, and the critical temperature and critical current density were measured by the four-terminal method for the central portion of 1 Omm width and 1 Omm length, and the results were obtained.
• the temperature is preferably set to 100 or less in order to obtain a critical current density of 5500 AZcm 2 or more.
• the film forming temperature range for obtaining a high critical current density is from 100 ° C. to 150 ° C., even within the range of 300 ° C. to ⁇ 150 ° C. A range of C is more preferred.
• Fig. 13 shows the film thickness dependence on the full width at half maximum of the polycrystalline thin film formed on the base tape. It shows the existence.
• FIG. 13 shows the result when the film was formed under the same conditions as above while holding the base tape at 100.
• the orientation of the [100] axis is beginning to stabilize at a film thickness exceeding 200 nm. Therefore, when the film is formed while irradiating the ion beam from an oblique direction at an incident angle of 50 to 60 degrees, some crystals whose crystal orientation is not well-aligned at the initial stage of film deposition are generated. However, as the thickness increases, the crystal orientation becomes better, and if the film thickness is 200 nm or more when viewed from the [100] axis orientation state, it is possible to obtain an excellent crystal orientation. It's clear what you can do. Next, Fig.
• FIG. 16 shows a comparison between the deposition temperature at 100 ° C and the temperature at 200 ° C in relation to the deposition time and the full width at half maximum of the YSZ polycrystalline thin film manufactured under the same conditions as described above.
• FIG. 17 shows a comparison between the film forming temperatures of 100 ° C. and 200 ° C. in relation to the thickness and full width at half maximum of the polycrystalline thin film of the same YSZ.

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• 1997
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